Does anyone else have a haunted truck? mine sure seems like it. it choses its own idle, will rev up randomly, or idle at 200-300 rpm.
granted it sounds kewl, but its not right. i belive its eletrical,but im not sure. ive been chasing it for like 4+ years. also the engine out put will change, i can be driving downthe road and it will just pick up speed with out downshifting or anything. and the cruse is screwed.. but thats another issue.
ive got 230000 on the truck, so its alowed to have some problems, but its just really weird.

ok that gives me a couple of places to start.
1. first thing to check is the throttle shaft to see if its worn to the point where its binding in the plate in the bore. it can and will do the goofy stuff you have discribed.
2. brake switch it can do things given its condition that will make you chase your tail. the guts of it wear out and when peices start moving inside its tricky to trace.

yeah i have the 5.2 with the 528? the 4 speed auto. i cant rememeber the numbers. anyway, yes its throttle by cable the cable is good, ( brand new) the throttle doesnt stick. itsnice and smooth. I have also checked the sensor to see if its signal is screwed up, but it maps out fine. i have gone through damn near everything on the truck eletrical wise, and everythign checks out.

last year it decided to just quit running for 3 months. tested everything, it lead to the computer, replaced that.. nothing. now i am runing on the orginal computer. but i have ran it with the replacement and it does the same thing. it is very irratic when it does all this stuff, i cant see any pattern so i have to guess that one sensor is having a glitch. but id be damn'd if i can find it.

how would the brake switch control it idleing? when it is in park/neutral. it also does the same idle in gear.and when it ganes power, it seems like the computer just switches the injector pulse width. it just slowly increases.

its not just me driving it either, friends have noticed it before when they drive it.